Arterial closure device

ABSTRACT

A hemodynamic flow assist device includes a miniature pump, a basket-like cage enclosing and supporting the pump, and a motor to drive the pump. The device is implanted and retrieved in a minimally invasive manner via percutaneous access to a patient&#39;s artery. The device has a first, collapsed configuration to assist in implantation and a second, expanded configuration once deployed and active. The device is deployed within a patient&#39;s aorta and is secured in place via a self-expanding cage which engages the inner wall of the aorta. The device includes a helical screw pump with self-expanding blades. Also included is a retrieval device to remove the hemodynamic flow assist device once it is no longer needed by the patient. Also included is an arterial closure device to close the artery access point after implantation and removal of the hemodynamic flow assist device. The hemodynamic flow assist device helps to increase blood flow in patients suffering from congestive heart failure and awaiting heart transplant.

CROSS-REFERENCE

The present application is a continuation application of U.S. patentapplication Ser. No. 13/761,544, entitled “Hemodynamic Assist Device”and filed on Feb. 7, 2013, which relies on U.S. Patent ProvisionalApplication No. 61/595,953, of the same title and filed on Feb. 7, 2012,for priority, both which are hereby incorporated by reference in theirentirety.

FIELD

The present specification relates generally to cardiovascular flowassist devices. More particularly, the present specification relates toan intravascular, collapsible pumping device that is implanted andremoved in a minimally invasive manner and which acts to increase bloodflow in hemodynamically compromised patients.

BACKGROUND

Heart failure is defined as a condition in which a person's heart is nolonger capable of supplying adequate blood flow to meet the needs of thebody. Congestive heart failure (CHF) refers to a condition wherein theheart does not transfer blood to end organs efficiently or it has to doso with increased filling pressures. CHF, rather than being its owndisease, occurs as a result of any one, or combination, of a number ofconditions which affect the heart, including, but not limited to,myocardial infarction, dilated cardiomyopathy, valvular heart disease,hypertension, obesity, diabetes, and cigarette smoking. All of theseconditions can lead to CHF by overloading or causing damage to the heartmuscle.

It has been estimated that nearly 5 million Americans have CHF.Increasing prevalence, hospitalizations, and deaths have made CHF amajor chronic condition in the United States and throughout the world.After the diagnosis of CHF, the death rate is 50% within 5 years. Eachyear, there are more than 400,000 new cases in the United States alone.The prevalence of CHF is increasing as the population ages.

Therapies for patients suffering from CHF include medical, surgical, andbiopharmaceutical (for example, growth factors, cytokines, myoblasts,and stem cells). Improvement in prognosis through medical therapy hasreached a ceiling. There is widespread thought that current medicaltherapies cannot be effectively expanded upon. Heart transplant is aneffective surgical remedy for patients with CHF. However, the demand faroutstrips the availability of donor hearts. Therefore, a mechanicalsolution is sorely needed to treat heart failure.

Typically for mechanical treatment of CHF, a pump such as a ventricularassist device (VAD) is implanted in a patient awaiting a hearttransplant. The VAD is implanted as a “bridge to transplant” or“destination therapy” for those weakened hearts that are expected tobecome unable to pump enough blood to sustain life. A VAD is typicallyattached to the left ventricle and draws blood from the left ventricleand sends the blood to the aorta.

A number of other devices have been proposed for assisting the diseasedheart and supporting decompensated hemodynamics. For example, U.S. Pat.No. 5,911,685, assigned to Impella Cardiosystems AG, describes “Anintravascular microaxial flow pump, comprising: a cylindrical drive unitof preselected outer diameter having an electric motor disposed thereindriving a shaft distally extending therefrom wherein such shaft issupported solely by two bearings, one located at the extreme proximalend of said drive unit and another at the extreme distal end of saiddrive unit; a cylindrical intravascular microaxial flow pump housingrigidly attached to said drive unit having essentially the samepreselected outer diameter and oriented to be coaxially and distallydisposed with respect to said drive unit; and an impeller disposedwithin said pump housing, rigidly affixed to said shaft, and locatedimmediately adjacent said distal bearing, operative to draw fluid intoand through said housing and over said drive unit.”

In addition, U.S. Pat. No. 7,125,376, assigned to Thoratec Corporation,describes “An intravascular extracardiac pumping system forsupplementing blood circulation through a patient experiencingcongestive heart failure without any component thereof being connectedto the patient's heart, the extracardiac system comprising: a pumpconfigured to pump blood through the patient at subcardiac volumetricrates, said pump having an average flow rate that, during normaloperation thereof, is substantially below that of the patient's heartwhen healthy, the pump configured to be positioned within thevasculature of a patient; an inflow conduit fluidly coupled to the pumpto direct blood to the pump, the inflow conduit configured to bepositioned within the vasculature of the patient; and an outflow conduitfluidly coupled to the pump to direct blood away from the pump, theoutflow conduit configured to be positioned within the vasculature ofthe patient; whereby the pump and the inflow and outflow conduits areconfigured so as to be inserted subcutaneously into the vasculature inan minimally-invasive procedure; and wherein the pump comprises animpeller.”

A cardiac recovery is possible for patients who suffer from CHF,especially through treatment with biopharmaceuticals. The likelihood ofcardiac recovery is believed to be increased by reducing the stress onthe heart from the decompensated state. However, the existence of a VADsurgically inserted into the heart reduces the likelihood of cardiacrecovery from CHF. The gold standard for treatment of advanced heartfailure is a heart transplant but the scarcity of transplantable heartsmakes this impossible for the vast majority of patients.

Therefore, there exists a need for a hemodynamic assist device that canbe implanted and retrieved in a minimally invasive manner, withoutdamaging the heart and preventing cardiac recovery.

SUMMARY

The present specification is directed toward an intravascular,hemodynamic flow assist device, comprising: a miniature helical screwpump with at least one collapsible blade; a collapsible cage structuresurrounding said pump; and, a motor to drive said pump; wherein saiddevice transforms from a first, collapsed configuration to a secondexpanded configuration, wherein the diameter of the first configurationis smaller than the diameter of the second configuration, and furtherwherein said device is converted into said first configuration duringimplantation and retrieval and converted into said second configurationfor deployment and operation.

In one embodiment, the intravascular hemodynamic flow assist devicecomprises a first shaft having a lumen, a proximal end, and a distalend; a second shaft having a proximal end and a distal end, wherein aportion of said proximal end of said second shaft is disposed within,and configured to telescope into and out of, a portion said lumen ofsaid first shaft at the distal end of said first shaft; at least one setof pump blades adapted to expand to an expanded configuration from afirst collapsed configuration and collapse from the expandedconfiguration back to said first collapsed configuration, wherein saidat least one set of pump blades is attached to said first shaft andarranged such that said first shaft has the form of a helical screwpump; a motor attached to said proximal end of said first shaft forcoaxially rotating said first shaft and said blades about said secondshaft to pump blood through the device; a housing encircling andcontaining said motor; a cap attached to said distal end of said secondshaft; a plurality of arms each having a proximal end and a distal end,wherein said proximal end of each of said plurality of arms is attachedto said housing and wherein said distal end of each of said plurality ofarms is attached to said cap; and a battery contained within saidhousing providing power to said motor, wherein said device istransformable between the first collapsed configuration and the expandedconfiguration, wherein the diameter of the first collapsed configurationis smaller than the diameter of the second expanded configuration,wherein said blades and said arms are compressed against said firstshaft when the device is in the first collapsed configuration, andwherein said blades expand away from said first shaft and said armsexpand away from said first shaft to form a cage surrounding said bladeswhen the device is in said expanded configuration.

Optionally, the hemodynamic flow assist device further comprises a wireattached to said motor, wherein said wire provides power and/or controlfrom a power and/or control device external to a patient. The blades andportions of said arms comprise a shape memory metal. The shape memorymetal is Nitinol. The hemodynamic flow assist device further comprises acoupling positioned between said proximal end of said first shaft andsaid motor for transferring rotation to said first shaft.

Optionally, the hemodynamic flow assist device further comprises atleast one sensor for sensing a functional parameter of said deviceand/or a physiological parameter of a patient, wherein data from saidsensor is transmitted to a controller and wherein said controller usessaid data to control said device. The hemodynamic flow assist devicefurther comprises at least one camera. The hemodynamic flow assistdevice further comprises a mechanism for changing a size of said cagebased on the size of a patient's aorta. The first shaft furthercomprises a plurality of compression rings to allow for deformation ofthe first shaft during placement.

Optionally, the hemodynamic flow assist device further comprises acompressible tubular cylinder having a lumen for directing blood flowinto said device, wherein said cylinder is positioned within said cageand is attached to said second shaft by at least one strut, furtherwherein said cylinder is compressed against said first shaft when saiddevice is in said first collapsed configuration. The hemodynamic flowassist device further comprises a self-charging battery or inverter,wherein said self-charging battery is charged by the unassisted flow ofblood turning said blades when a patient having said device implanted isin the prone position.

Optionally, the hemodynamic flow assist device further comprises anaccelerometer, wherein said accelerometer detects a position of apatient and generates data indicative of said position, and wherein acontroller receives said data and causes a rotational speed of thedevice to adjust accordingly. The cage has a cone shape configured toresist dislodgement within a patient's aorta.

In another embodiment, an intravascular hemodynamic flow assist devicecomprising: a first shaft having a lumen, a proximal end, and a distalend; a second shaft having a proximal end and a distal end, wherein aportion of said proximal end of said second shaft is disposed within,and configured to telescope into and out of, a portion said lumen ofsaid first shaft at the distal end of said first shaft; at least one setof collapsible pump blades attached to said first shaft, said bladesarranged such that said first shaft forms a helical screw pump; a motorattached to said proximal end of said first shaft for coaxially rotatingsaid first shaft and said at least one set of collapsible blades aboutsaid second shaft to pump blood through the device; a housing encirclingand containing said motor; a cap attached to said distal end of saidsecond shaft; an elongate, collapsible tubular cylinder having a lumen,a proximal end, and a distal end, wherein said cylinder is attached tosaid second shaft by a plurality of struts; and, a battery containedwithin said housing providing power to said motor.

In another embodiment, an intravascular hemodynamic flow assist devicecomprises a first shaft having a lumen, a proximal end, and a distalend; a second shaft having a proximal end and a distal end, wherein aportion of said proximal end of said second shaft is disposed within,and configured to, telescope into and out of, a portion said lumen ofsaid first shaft at the distal end of said first shaft; a first bearingcoupled to and coaxially rotatable about said proximal end of said firstshaft; a second bearing coupled to and coaxially rotatable about saiddistal end of said second shaft; at least one set of collapsible pumpblades attached at a first end to said first bearing and at a second endto said second bearing, said blades arranged such that said first shaftand second shafts form a helical screw pump; a housing attached to saidproximal end of said first shaft; a cap attached to said distal end ofsaid second shaft; and, a plurality of arms each having a proximal endand a distal end, wherein said proximal end of each of said plurality ofarms is attached to said housing and wherein said distal end of each ofsaid plurality of arms is attached to said cap; wherein portions of saidarms are magnetically charged and cause said blades to spin via magneticcoupling; wherein said device is transformable between a first,collapsed configuration and a second expanded configuration, wherein thediameter of the first configuration is smaller than the diameter of thesecond configuration, further wherein said device is converted into saidfirst configuration during implantation and retrieval and converted intosaid second configuration for deployment and operation, further whereinsaid second shaft partially telescopes distally out of said first shaftand said blades and said arms are compressed against said first shaftwhen the device is in said first configuration, further wherein saidsecond shaft partially telescopes proximally into said first shaft, saidblades expand away from said first shaft, and said arms expand away fromsaid first shaft to form a cage surrounding said blades when the deviceis in said second configuration, still further wherein said arms contactan inner wall of an aorta to hold the device in place.

In another embodiment, the present specification discloses a method ofimplanting the hemodynamic flow assist devices disclosed above, wherethe method comprises: providing a tubular sheath having a lumen, aproximal end, a distal end, and a guide wire disposed within said lumen;creating an access point into an artery of a patient; inserting saidsheath and wire into said artery and advancing it such that said distalend of said sheath is positioned within said patient's descending aorta;inserting said flow assist device, in said first configuration, intosaid sheath and advancing it along said guide wire to said distal end ofsaid sheath; providing a positioning device comprising an elongateflexible shaft having a proximal end and a distal end, wherein saiddistal end is coupled to said housing of said flow assist device andsaid proximal end is manipulated by a physician; using said positioningdevice to advance said flow assist device beyond said distal end of saidsheath and to position said flow assist device within said patient'saorta, wherein said flow assist device passively expands from said firstconfiguration to said second configuration once it is beyond said distalend of said sheath; uncoupling said positioning device from said flowassist device and removing said positioning device and said sheath fromsaid aorta via said artery; and, closing said access point in saidartery.

Optionally, the artery is any one of a femoral, external iliac, commoniliac, subclavian, brachial, and axillary artery. The flow assist deviceis positioned within said descending aorta between a leftbrachiocephalic trunk and a point distal a renal artery.

In another embodiment, the specification discloses a blood vesselclosure device comprising: an elongate tubular sheath having a sheathlumen, a proximal end, and a distal end; an elongate tamper tooldisposed within said sheath lumen and having a tool lumen, a proximalend, and a distal end wherein said distal end of said tool is positionedproximate and within said distal end of said sheath and said proximalend of said tool extends beyond said proximal end of said sheath,further wherein said tool includes a handle at said proximal end; and apair of compressible discs positioned within said distal end of saidsheath distal to and in contact with said distal end of said tool, saiddiscs connected by a center member and transformable between a firstconfiguration and a second configuration, wherein said discs arecompressed and have a tubular shape when in said first configuration andare expanded and have an umbrella shape when in said secondconfiguration, further wherein said discs are deployable beyond saiddistal end of said sheath by pushing on said handle of said tool suchthat said tool moves distally into said sheath and pushes out saiddiscs; further wherein said discs are in said first configuration whendisposed within said sheath and are in said second configuration whenadvanced beyond said distal end of said sheath; wherein, when said discsare deployed in said second configuration, a first distal disc ispositioned within a blood vessel and a second proximal disc ispositioned outside the blood vessel with the center member occluding anopening in a wall of said blood vessel.

In another embodiment, the present specification discloses a method ofclosing an opening in a blood vessel wall using the closure devicedisclosed above, where the method comprises the steps of: providing aguide wire having a proximal end and a distal end; inserting a saiddistal end of said guide wire into said blood vessel through saidopening; inserting said proximal end of said guide wire into said toollumen and advancing said closure device along said guide wire;positioning said distal end of said sheath in the interior of said bloodvessel; pushing on said handle of said tool of said closure device toadvance a distal disc beyond said distal end of said sheath, said distaldisc passively expanding into said second configuration within saidblood vessel; pulling back on said closure device to position saiddistal disc against an inner wall of said blood vessel; pushing on saidhandle of said tool of said closure device to advance a proximal discbeyond said distal end of said sheath, said proximal disc passivelyexpanding into said second configuration outside of said blood vesseland resting against an outer wall of said blood vessel such that thedistal and proximal discs and center member act to occlude said openingin said blood vessel; and, removing said sheath with said tool and saidguidewire.

The aforementioned and other embodiments of the present invention shallbe described in greater depth in the drawings and detailed descriptionprovided below.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will befurther appreciated, as they become better understood by reference tothe detailed description when considered in connection with theaccompanying drawings:

FIG. 1 is an oblique front view illustration of one embodiment of thecardiovascular flow assist device in the expanded, deployedconfiguration;

FIG. 2 is an oblique, cross-sectional illustration of an aorta depictingone embodiment of the cardiovascular flow assist device in the expanded,deployed configuration positioned therein;

FIG. 3 is an oblique front view illustration of one embodiment of thecardiovascular flow assist device in the collapsed, deliverableconfiguration;

FIG. 4A is an oblique, front view illustration depicting one embodimentof a cardiovascular flow assist device in the expanded, deployedconfiguration side by side with another cardiovascular flow assistdevice in the collapsed, deliverable configuration;

FIG. 4B is a side view illustration depicting the same embodiment of acardiovascular flow assist device in the expanded, deployedconfiguration side by side with another cardiovascular flow assistdevice in the collapsed, deliverable configuration, of FIG. 4A;

FIG. 5A is a side view illustration of one embodiment of thecardiovascular flow assist device in the expanded, deployedconfiguration, depicting two cage support members removed from eitherside of the helical screw pump;

FIG. 5B is an oblique, side view illustration of one embodiment of anouter shaft portion blade attachment segment, with one attached blade,of the cardiovascular flow assist device;

FIG. 6A is an oblique, front view illustration of one embodiment of thehelical screw pump of the cardiovascular flow assist device, depictingtwo sets of helical blades in the expanded configuration;

FIG. 6B is a side view illustration of the same embodiment of thehelical screw pump of the cardiovascular flow assist device, depictingtwo sets of helical blades in the expanded configuration, of FIG. 6A;

FIG. 7A is an oblique, front view illustration of one embodiment of thehelical screw pump of the cardiovascular flow assist device in theexpanded configuration, depicting one set of helical blades;

FIG. 7B is a side view illustration of the same embodiment of thehelical screw pump of the cardiovascular flow assist device, depictingone set of helical blades in the expanded configuration, of FIG. 7A;

FIG. 7C is a front-on view illustration of the same embodiment of thehelical screw pump of the cardiovascular flow assist device, depictingone set of helical blades in the expanded configuration, of FIG. 7A;

FIG. 8A is an oblique, front view illustration of one embodiment of thehelical screw pump of the cardiovascular flow assist device, depictingone set of helical blades in the collapsed configuration;

FIG. 8B is a side view illustration of the same embodiment of thehelical screw pump of the cardiovascular flow assist device, depictingone set of helical blades in the collapsed configuration, of FIG. 8A;

FIG. 8C is a front-on view illustration of the same embodiment of thehelical screw pump of the cardiovascular flow assist device, depictingone set of helical blades in the collapsed configuration, of FIG. 8A;

FIG. 9A is an oblique, front view illustration of one embodiment of twocage support members formed together into a singular cage arm in theexpanded configuration;

FIG. 9B is a side view illustration of the same embodiment of two cagesupport members formed together into a singular cage arm in the expandedconfiguration of FIG. 9A;

FIG. 9C is a top-down view illustration of the same embodiment of twocage support members formed together into a singular cage arm in theexpanded configuration of FIG. 9A;

FIG. 9D is a front-on view illustration of the same embodiment of twocage support members formed together into a singular cage arm in theexpanded configuration of FIG. 9A;

FIG. 10A is an oblique, front view illustration of one embodiment offour cage arms combined together to form a complete basket-like cage inthe expanded configuration;

FIG. 10B is a side view illustration of the same embodiment of four cagearms combined together to form a complete basket-like cage in theexpanded configuration of FIG. 10A;

FIG. 10C is a front-on view illustration of the same embodiment of fourcage arms combined together to form a complete basket-like cage in theexpanded configuration of FIG. 10A;

FIG. 11A is an oblique, front view illustration of one embodiment offour cage arms combined together to form a complete basket-like cage inthe collapsed configuration;

FIG. 11B is a side view illustration of the same embodiment of four cagearms combined together to form a complete basket-like cage in thecollapsed configuration of FIG. 11A;

FIG. 11C is a front-on view illustration of the same embodiment of fourcage arms combined together to form a complete basket-like cage in thecollapsed configuration of FIG. 11A;

FIG. 12A is a side view illustration on one embodiment of an arterialclosure device, depicting the arterial closure discs of the devicepositioned within a delivery sheath;

FIG. 12B is a side view illustration of the same embodiment of thearterial closure device of FIG. 12A, depicting the distal arterialclosure disc expanded and deployed from the distal end of the deliverysheath;

FIG. 12C is a side view illustration of the same embodiment of thearterial closure device of FIG. 12A, depicting both the distal andproximal arterial closure discs expanded and deployed from the distalend of the delivery sheath;

FIG. 12D is a side view illustration of one embodiment of the arterialclosure discs fully deployed with the delivery sheath removed;

FIG. 12E is an illustration of one embodiment of the arterial closurediscs, depicting the struts used to expand the discs to their deployedconfiguration;

FIG. 13 is a flowchart illustrating the steps involved in implanting thehemodynamic flow assist device in the descending aorta of a patient, inaccordance with one embodiment of the present specification; and,

FIG. 14 is a flowchart illustrating the steps involved in closing anarterial access point using the arterial closure device, in accordancewith one embodiment of the present specification.

DETAILED DESCRIPTION

The present specification is directed toward an intravascular,collapsible pumping device that is implanted and removed in a minimallyinvasive manner and which acts to increase blood flow in hemodynamicallycompromised patients. The device is positioned within the aorta,downstream of the aortic arch, and offloads the diseased heart byincreasing systemic blood flow. In one embodiment, the device is anelongate, cylindrically shaped device with a proximal end and a distalend, comprising a miniature pump, a basket-like cage enclosing saidpump, and a motor to drive the pump. In one embodiment, power for themotor is supplied by an internal battery. In another embodiment, atleast one wire extends from the proximal end of the device and providespower to the device.

Optionally, in one embodiment, the wire also provides control for thedevice. In one embodiment, the device includes a cap at its distal end.In one embodiment, the pump is a helical screw pump, such as anArchimedes' pump, comprising a rotating shaft with at least one set ofcollapsible pump blades attached thereto. In one embodiment, therotating shaft comprises an inner portion and an outer portion, whereinthe inner portion is capable of slidable movement partially into and outof the outer portion. In one embodiment, preloaded compressionseparating rings on the shaft provide fluid tight seals and allow forany axial displacement introduced by flexible coupling and pressure onthe pump blades. The cage is comprised of a multitude of support membersand provides support to the pump and anchors the pump within thedescending aorta. The pump blades and portions of the cage supportmembers are composed of a shape memory metal that allows the device tochange from a first, deliverable and collapsed configuration into asecond, deployed and expanded configuration. In one embodiment, the pumpblades and portions of each support member are composed of Nitinol. Inone embodiment, as the device is collapsed, the inner portion of therotating shaft extends partially from the outer portion, causing thedevice to become elongated when in the collapsed configuration. At thesame time, the pump blades and cage support members collapse in towardthe center of the device, resulting in the total diameter of the devicebeing decreased while in the collapsible configuration.

In one embodiment, the intravascular, collapsible pumping device of thepresent specification includes at least one sensor. In one embodiment,the sensor is a full 3D space profile pressure quad-sensor. In anotherembodiment, the sensor is an inflow quad-sensor. In another embodiment,the sensor is a temperature and outflow quad-sensor. The sensor is usedto relay information regarding the initial positioning and initialaortic wall proximity, based on differentials of comparable sensor pairsat any stage of the device. In one embodiment, the sensor provides thehealth care professional with vital device functionality information. Inanother embodiment, the device includes two or more sensors positionedat different locations along the length of the device. In oneembodiment, a first sensor is positioned proximate the distal end of thedevice and a second sensor is positioned proximate the proximal end ofthe device. Differences in values measured between the first sensor andthe second sensor are used to determine rates of flow and functionalityof the device. In one embodiment, the intravascular, collapsible pumpingdevice of the present specification includes at least one camera. In oneembodiment, the camera is positioned proximate the distal end of thedevice. In one embodiment, the camera is an infra-red (IR) chargedcoupled device (CCD) camera.

In one embodiment, the device is implanted percutaneously through apatient's artery. In one embodiment, the device is introduced via thefemoral artery. In another embodiment, the device is introduced via theexternal iliac artery. In another embodiment, the device is introducedvia the common iliac artery. In yet another embodiment, the device isintroduced via the subclavian artery. In one embodiment, a puncture ismade in the patient's thigh area and a sheath is introduced into thefemoral artery and its distal end is positioned in the aorta. The deviceis mechanically inserted into the sheath. The sheath has a diameter thatis smaller than the diameter of the device in its expanded configurationand is larger than the diameter of the device in its collapsedconfiguration. In one embodiment, the act of inserting the device intothe sheath causes the device to compress into its collapsedconfiguration. The sheath and collapsed device are advanced into thepatient's aorta to the desired deployment location. In one embodiment,the device is deployed in the descending aorta just downstream from theleft brachiocephalic trunk. In another embodiment, the device isdeployed in the descending aorta just downstream from the renalarteries. In various other embodiments, the device is deployed anywherealong the descending aorta between the left brachiocephalic trunk andjust downstream from the renal arteries, with care taken not to occludeany branches contained therewithin. In various other embodiments, accessis obtained through the subclavian, axillary or brachial arteries.

Once the sheath and device have reached the desired deployment location,the sheath is retracted while the device is held in place by an attachedpositioning shaft. The positioning shaft is an elongate, flexible, solidshaft having a proximal end and a distal end. The distal end of theshaft attaches to the proximal end of the device with either a screw orclip and the shaft traverses the entire length of the sheath. Theproximal end of the shaft exits from the proximal end of the sheath andincludes a proximal knob that can be manipulated outside the sheath. Theshaft is detached from the device via an unlock mechanism after thedevice is positioned appropriately. In one embodiment, once the sheathhas cleared the device, the pump blades and cage support members expandand the inner portion of the rotating shaft telescopes partly into theouter portion of said shaft. In another embodiment, a distal portion ofthe rotating shaft extends partially into the distal cap when in theexpanded configuration. In this embodiment, the distal cap comprises afluid filled cavity to accommodate a distal portion of the rotatingshaft. The fluid is eliminated when the cage expands. As the devicechanges into its deployed, expanded configuration, its length shortensand diameter increases. The cage support members come to rest upon thewalls of the aorta and the rotating shaft with attached pump blades isfree to spin within the cage. The positioning shaft is disengaged fromthe proximal end of the device and removed from the sheath. The sheathis then removed from the patient. In an embodiment in which the devicehas an internal battery, the puncture site is sutured close. In analternate embodiment, in which the device includes a power and/orcontrol wire, said wire extends from the puncture site and is secured atthe patient's skin. In one embodiment, the wire extends to a batteryand/or control pack which sits in a belt or vest at the belt level.

The present specification is also directed toward a retrieval deviceused to remove the pumping device from the patient's aorta. In oneembodiment, the retrieval device is similar to the one described in U.S.Pat. No. 7,878,967, entitled “Heart Failure/Hemodynamic Device” andassigned to the applicant of the present invention, which is herebyincorporated in its entirety. In one embodiment, when the pumping deviceis ready to be removed, a sheath is once again introduced percutaneouslyinto the femoral artery using the power and/or control wire, ifremaining. In another embodiment, the control and the power wirescomprise at least two separate wires coming from diagonally oppositeends of the proximal portion of the device. The removal device is theninserted into the sheath and both are advanced through the vasculatureinto the descending aorta and up to the pumping device. The retrievaldevice is then advanced further beyond the end of the sheath. The distalend of the retrieval device interfaces with the proximal end of thepumping device such that the pumping device becomes connected to theretrieval device. This connection can be a mechanical locking mechanismor magnetically assisted. The retrieval device is then retracted backinto the sheath, bringing the pumping device with it. The attachedproximal wires and enclosing wires jacket that, in one embodiment, isreinforced for added strength can be used to pull the device into thesheath. As the cage comes into contact with the sheath, the supportmembers are compressed back toward the center of the pumping device.Compression of the cage causes the inner portion of the rotating shaftto partially extend out from the outer portion of said rotating shaft.In another embodiment, wherein the distal cap comprises a cavity tohouse a distal portion of the shaft, the distal cap extends away fromthe shaft and said cavity fills with blood during retrieval. In oneembodiment, as the cage gradually collapses, the shaft with helical pumpblades rotates reversely. The initial blade shape and the fully expandedblade shape are developed with a blade profile such that when rotatedreversely allow the blades to be deformed and take a similar shape as inthe insertion stage. In one embodiment, the inner construction anddetails of the enclosed cage will provide further support and guidanceto the pump blades to assist in their deformation and effectively placethem in the inside space of the compressed cage. Compression of the cagesupport members and extension of the rotating shaft inner portion resultin collapse of the helical pump blades. Pulling of the pumping deviceinto the sheath via the attached retrieval device causes the pumpingdevice to revert back to its collapsed, retrievable configuration. Oncefully withdrawn into the sheath, the pumping device, along with theattached retrieval device and sheath, is removed through the femoralartery and the access site is sutured closed. In one embodiment, asieve-like filter is attached to the distal end of the retrieval device.This circular filter is deployed when the retrieval device is extendedbeyond the distal end of the sheath. The filter traps any debris that isdislodged in the process of retrieving the pumping device. The filterthen also collapses into the sheath along with the device after thedevice is retracted into the sheath.

In one embodiment, retrieval of the device employs two wires attached tothe proximal end of the pumping device. A retrieval device is insertedinto the access vessel using the two wires as rails to guide theretrieval device to the pumping device. In one embodiment, the wires canbe used to elongate the shaft of the pumping device when put on tension,thereby collapsing the device prior to retrieval.

In another embodiment, wherein the pumping device includes an internalbattery and no wires extend from the body of the patient, retrieval ofthe device employs magnetism. The proximal end of the pumping device andthe distal end of the retrieval device are magnetized with oppositepolarities so that the two will connect when the retrieval device isadvanced to the deployed pumping device.

Optionally, in one embodiment, the rotating shaft of the pump iscomprised of a stretchable material rather than inner and outerportions. When the device is collapsed, the shaft stretches, increasingthe length of the device. Once released from the insertion sheath, theshaft contracts to its default shape. In this embodiment, the at leastone set of blades is attached only at the proximal and distal ends ofthe shaft. As the shaft is stretched, the blades and cage supportmembers stretch and compress toward the center of said shaft. As theshaft contracts to its default shape, the blades return to theiroperable, expanded configuration.

Optionally, in one embodiment, the at least one set of blades isattached only to bearings positioned at the proximal and distal ends ofthe shaft. In this embodiment, only the blades rotate with the bearings.In one embodiment, the blades are rotated via magnetic coupling. Theshaft does not rotate, resulting in fewer moving parts and lower powerconsumption. This embodiment can be utilized on a telescoping shaft or astretchable shaft as described above.

Optionally, in one embodiment, the basket-like cage acts as a stator androtates the blades such that the entire helical blade set(s) and cageare magnetically active and become a rotor of the coreless motor,eliminating the need for an electric motor at the proximal end of thedevice. In this embodiment, the blades are composed of a magnetic fieldmaterial and the cage components possess the ability to electricallyinduce a polarized magnetic field.

Optionally, in one embodiment, the device includes a collapsible,continuous cylinder positioned just within the cage. The cylinder isopen at its distal and proximal ends to allow for the passage of blood.The space between the blades of the pump and the cylinder is minimal,improving the efficiency of the device by decreasing the amount ofleakage around the blades. In one embodiment, the blades and thecylinder are like charged so that the cylinder would be magneticallylevitated and not come into contact with the blades.

Optionally, in one embodiment, the device includes a collapsible,continuous cylinder in place of the basket-like cage. The cylinder isopen at its distal and proximal ends to allow for the passage of blood.The outside circumference of the cylinder rests upon the inner wall ofthe aorta. In one embodiment, the cylinder is attached to the device viacollapsible struts. The space between the blades of the pump and thecylinder is minimal, improving the efficiency of the device bydecreasing the amount of leakage around the blades.

Optionally, in one embodiment, the device includes a mechanism to adjustthe diameter of the device in the deployed configuration dependent uponthe size of the patient's aorta. In one embodiment, the power/controlwire leading from the proximal end of the device enables the physicianto dial in the cage diameter by extending or retracting the inner shaftportion within the outer shaft portion.

Optionally, in one embodiment, the device is designed in a manner suchthat when in the expanded configuration, said device takes on a slightlyelliptical shape in which the proximal end is slightly smaller indiameter than the distal end. Such a design provides at least twobenefits. First, the device sits in the aorta like a cone, resistingmigration caused by the constant blood flow and forward pressureexperienced by the device. Second, the device is easier to retrieve asit fits more easily back into the sheath.

Optionally, in one embodiment, magnetic coupling is used between themotor and the pump with the motor parts being hermetically sealed sothat no fluid seepage can occur.

Optionally, in one embodiment, the device includes a self-chargingbattery in its proximal end. In this embodiment, the device includes aninverter. While the patient is at rest and the device is not in use,inertia and momentum caused by the blood flow generated by the heartcontinues to rotate the blades and is stored as energy for use when thedevice is in operation.

Optionally, in one embodiment, the device includes an accelerometer todetect increased movement by the patient, signifying increased physicalactivity. Based on the heightened physical activity, the deviceincreases blood flow to meet demands. Conversely, if the accelerometerdetects decreased physical activity, the device will decrease bloodflow. In another embodiment, the device includes a flow meter. The flowmeter will detect increased blood flow from the heart during heightenedphysical activity and the device will in turn increase speed andtherefore blood flow. In one embodiment, the flow meter sends data tothe patient via the cable attached to the proximal end of the device.The patient can then increase or decrease blood flow provided by thedevice based upon values obtained from the flow meter.

Optionally, in one embodiment, the distal end cap includes a mechanismthat assists in the transformation of the device from the collapsedconfiguration into the deployed configuration. The distal cap is hollowand contains a biocompatible fluid that is used to provide hydraulics tochange the device between collapsed and expanded shapes.

The device of the present specification increases blood flow to the bodyparts located downstream of said device, thereby decreasing strain uponthe diseased heart. As demand on the heart is lessened, the heart muscleis able to rest and, over time, partially repair itself In oneembodiment, the helical screw pump of the device spins at a variablerate that is fully controlled in a closed loop via a monitoring andcontrolling computer. In one embodiment, the helical screw pump of thedevice spins at a rate within a range of 100 to 1000 rpms. The lowerspeed allows for greater energy efficiency and decreased red blood celldestruction caused by the pump. In one embodiment, at least anadditional 2.5 L/min of blood flow is provided by the device of thepresent specification. In various embodiments, additional blood flowgreater than the amount of 2.5 L/min, and greater than that provided bya normally functioning heart at rest (about 5 L/min) are provided by thedevice of the present specification. Without assistance, the compromisedheart would not be able to sustain adequate blood flow to the body,resulting in continual worsening of heart failure, eventually leading todeath of the patient.

The present specification is also directed toward an arterial closuredevice used to close the access point in the artery followingimplantation or removal of the pumping device. In one embodiment, thearterial closure device comprises a sheath having a lumen, a proximalend, and a distal end. Disposed within the distal end of the sheath is apair of arterial closure discs connected by a center member. When in thesheath, the discs are compressed into a tubular configuration. A tampertool having a proximal end and a distal end extends within the lumen ofthe sheath. The proximal end of the tamper tool includes a handle andthe distal end abuts the proximal disc of the pair of arterial closurediscs. A physician places the distal end of the sheath in the arterythrough the access site. The physician then pushes on the handle of thetamper tool which causes the distal disc to extend beyond the distal endof the sheath and into the artery. As the distal disc extends, itexpands into an umbrella shape. The physician then pulls back on thedevice such that the distal disc abuts the inner wall of the artery.Pushing again on the handle extends the proximal disc beyond the distalend of the sheath. The proximal disc also expands into an umbrella shapeand comes to rest on the outer wall of the artery, effectively closingthe arterial access site.

The present invention is directed toward multiple embodiments. Thefollowing disclosure is provided in order to enable a person havingordinary skill in the art to practice the invention. Language used inthis specification should not be interpreted as a general disavowal ofany one specific embodiment or used to limit the claims beyond themeaning of the terms used therein. The general principles defined hereinmay be applied to other embodiments and applications without departingfrom the spirit and scope of the invention. Also, the terminology andphraseology used is for the purpose of describing exemplary embodimentsand should not be considered limiting. Thus, the present invention is tobe accorded the widest scope encompassing numerous alternatives,modifications and equivalents consistent with the principles andfeatures disclosed. For purpose of clarity, details relating totechnical material that is known in the technical fields related to theinvention have not been described in detail so as not to unnecessarilyobscure the present invention.

FIG. 1 is an oblique front view illustration of one embodiment of thecardiovascular flow assist device 100 in the expanded, deployedconfiguration. In the pictured embodiment, the device 100 includes twosets of helical pump blades 104. Each blade 104 includes a multitude ofsmall fenestrations 105. These fenestrations 105 impart increasedflexibility to each blade 104 so that the blades will be easier tocompress without sacrificing efficiency of the pump. Each blade 104 isconnected to a portion of the rotating pump shaft, which is not easilyvisualized in this figure but is further discussed with reference toFIGS. 5A-6B. A cable 108 extends from the proximal end of the device 100and, in various embodiments, carries power supply and/or control wiresfrom outside the body to the device 100. The device 100 includes eightcage support members 120 encircling the pump. In one embodiment, twosupport members 120 are manufactured together in one piece to assist inassembly of the device, as will be further discussed with reference toFIGS. 9A-9D. In one embodiment, the device 100 includes a cap 106 at itsdistal end. In one embodiment, the distal end cap 106 is cone shaped. Inthe pictured embodiment, the distal end cap 106 includes four sensors132 positioned equidistant from one another proximate the distal tip ofsaid end cap 106. Four additional sensors 134 are positioned proximatethe distal end of every second cage support member 120, such that everysupport member 120 containing a sensor is adjacent to a support member120 without a sensor. Each support member 120 containing a distal endsensor 134 also has an additional sensor 136 proximate its proximal end,resulting in a total of twelve sensors on the device 100. Althoughtwelve sensors are depicted in the pictured embodiment, any number ofsensors may be used to provide the health care professional informationregarding the functionality of the device 100. Data gathered by thesensors is transferred to a processor outside the patient via cable 108.

FIG. 2 is an oblique, cross-sectional illustration of an aorta 240depicting one embodiment of the cardiovascular flow assist device 200 inthe expanded, deployed configuration positioned therein. When deployed,the diameter of the cage of the device 200 is slightly larger than theinternal diameter of the aorta, such that the cage support members 220contact the inner wall of the aorta. Each cage support member 220becomes fixes in place against the aortic wall, securing the device 200within the aorta 240. The pump is then free to rotate within the supportcage, increasing blood flow downstream from the device 200.

FIG. 3 is an oblique front view illustration of one embodiment of thecardiovascular flow assist device 300 in the collapsed, deliverableconfiguration. In the pictured embodiment, the device 300 includes adistal end cap 306 with sensors 332 and a power/control cable 308emanating from its proximal end. The cage support members 320 arecollapsed in toward the center of the device 300, forming an elongate,streamlined cylindrical shape. This collapsed configuration enables thephysician to implant the device in a percutaneous fashion, avoiding amore invasive surgical procedure and resulting in less stress anddiscomfort to the patient.

FIGS. 4A and 4B are oblique front and side illustrations respectively,depicting one embodiment of a cardiovascular flow assist device 400 inthe expanded, deployed configuration side by side with anothercardiovascular flow assist device 401 in the collapsed, deliverableconfiguration. The cage support members 420 of the deployed device 400are seen in their fully expanded state, exposing the pump and helicalpump blades 404. The cage support members 421 of the collapsed device401 are seen in their fully compressed state, collapsed toward thecenter of the device and coming to rest in contact with one another. Ascan be seen in FIGS. 4A and 4B, the diameter of the device 400 when inthe expanded configuration, particularly the diameter of the cage, islarger than the diameter of the device 401 when in the collapsedconfiguration. In one embodiment, the diameter of the device 400 in theexpanded configuration is in the range of 15-30 mm. In one embodiment,the diameter of the device 400 in the expanded configuration is 25 mm.In one embodiment, the diameter of the device 401 in the collapsedconfiguration is in the range of 3-8 mm. In one embodiment, the diameterof the device 401 in the collapsed configuration is 6 mm. As can also beseen in FIGS. 4A and 4B, the length of the device 400 when in theexpanded configuration is shorter than the length of the device 401 whenin the collapsed configuration. In one embodiment, the length of thedevice 400 when in the expanded configuration is in the range of 20-90mm. In one embodiment, the length of the device 401 when in thecollapsed configuration is in the range of 30-100 mm.

FIG. 5A is a side view illustration of one embodiment of thecardiovascular flow assist device 500 in the expanded, deployedconfiguration, depicting two cage support members 520 removed fromeither side of the helical screw pump 503. The end cap (not shown) hasalso been removed from the device 500 pictured in FIG. 5A. Thesecomponents have been removed to provide enhanced visualization of thehelical screw pump 503 of the device 500. In one embodiment, the helicalscrew pump 503 comprises an elongate, cylindrical inner shaft portion511, a distal outer shaft portion segment 512, four outer shaft portionblade attachment segments 514, five outer shaft portion spacer segments513, and a proximal outer shaft portion segment 516. The pump 503 isconnected at its proximal end, via a coupling 507, to a motor 509. Inone embodiment, the coupling 507 is a low friction flexible couplingwhich transfers rotation from the motor 509 to the shaft. The coupling507 acts to keep the motor 509 and shaft in alignment and preventsbinding and stoppage of the motor 509. In the pictured embodiment, thepump 503 includes two sets of helical blades 504. Each outer bladeattachment segment 514 of the pump 503 shaft includes two attachedblades 504 positioned 180 degrees apart on either side of said segment514. Each of the two blade sets comprises four separate blades 504. Invarious embodiments, the pitch of each blade in the deployedconfiguration is within the range of 20 to 70 degrees. In oneembodiment, the pitch of each blade in the deployed configuration is 45degrees. The blades 504 in each set join to form a continuous helicalscrew spiraling around either side of the pump 503. Having two sets ofblades 504 improves performance of the pump by increasing pumpingefficiency and by balancing the pump 503. In addition, having the pumpblades formed in segments eases collapsibility and allows for intendeddeformation to create the smallest outside profile for minimallyinvasive intravascular insertion. In one embodiment, each blade 504includes a multitude of fenestrations 505 to increase flexibility of theblades for compression and expansion. In one embodiment, the blades 504are coated in silicon to prevent blood flow through the fenestrations505.

In one embodiment, the inner shaft portion 511 of the pump extendsthrough to the coupling 507 and is slidably movable within the pump'souter shaft portion segments 512, 514, 513, 516. This allows the deviceto lengthen and shorten during compression and expansion respectively.In one embodiment, the distal end of the inner shaft portion 511 of thepump 503 and the distal ends of the cage support members 520 attach tothe distal end cap (not shown). To lend linear stability to the device500, in one embodiment, the inner shaft portion 511, distal outer shaftportion segment 512, outer shaft portion blade attachment segments 514,and proximal outer shaft portion segment 516 are composed of stainlesssteel. In one embodiment, the outer shaft portion spacer segments 513are composed of silicon to absorb pressure during compression andexpansion of the device 500. As mentioned earlier, the blades 504 arecomposed of a shape memory metal to allow for compression and expansionof said blades 504. In one embodiment, the shape memory metal isNitinol. In one embodiment, the device 500 includes a Teflon motor seal.

FIG. 5B is an oblique, side view illustration of one embodiment of anouter shaft portion blade attachment segment 514, with one attachedblade 504, of the cardiovascular flow assist device. In one embodiment,each blade 504 is laser welded to each segment 514 at two points 517along the outer circumference of the segment 514, with a gap 518 inbetween the two weld points 517. The gap 518, along with thefenestrations 505 in the blade 504, lends greater flexibility to theblade 504 to ease blade compression and expansion.

FIG. 6A is an oblique, front view illustration and FIG. 6B is a sideview illustration of one embodiment of the helical screw pump 603 of thecardiovascular flow assist device, depicting two sets of helical blades604 in the expanded configuration. The distal end cap and cage have beencompletely removed to enhance pump 603 visualization. In the embodimentdepicted in FIGS. 6A and 6B, the pump 603 does not include a couplingand the entirety of the motor 609 can be seen. Also visible are theinner shaft portion 611, distal outer shaft portion segment 612, outershaft portion blade attachment segments 614, outer shaft portion spacersegments 613, and proximal outer shaft portion segment 616.

FIGS. 7A, B, and C are oblique front, side, and front-on viewillustrations respectively, of one embodiment of the helical screw pump703 of the cardiovascular flow assist device, depicting one set ofhelical blades 704 in the expanded configuration. The distal end cap andcage have been completely removed to enhance pump 703 visualization.Referring simultaneously to FIGS. 7A and 7B, the pictured embodiment ofthe pump 703 does not include a coupling and the entirety of the motor709 can be seen. Also visible are the inner shaft portion 711, distalouter shaft portion segment 712, outer shaft portion blade attachmentsegments 714, outer shaft portion spacer segments 713, and proximalouter shaft portion segment 716. FIG. 7C illustrates how each blade 704meets the other to form a virtually seamless helical screw.

FIGS. 8A, 8B, and 8C are oblique front, side, and front-on viewillustrations respectively, of one embodiment of the helical screw pumpof the cardiovascular flow assist device, depicting one set of helicalblades in the collapsed configuration. The distal end cap, cage,coupling, and motor have been completely removed to enhance pump 803visualization. Referring simultaneously to FIGS. 8A and 8B, the innershaft portion 811, distal outer shaft portion segment 812, outer shaftportion blade attachment segments 814, outer shaft portion spacersegments 813, and proximal outer shaft portion segment 816 are allvisible. FIG. 8C illustrates how each blade 804 compresses in toward thebody of the pump shaft while in the collapsed configuration.

FIG. 9A is an oblique, front view illustration and FIG. 9B is a sideview illustration of one embodiment of two cage support members 920formed together into a singular cage arm 950 in the expandedconfiguration. Referring simultaneously to FIGS. 9A and 9B, while in theexpanded configuration, the two cage support members 920 of each cagearm 950 are expanded outward from the pump (not shown) and from oneanother. At the distal end of each cage arm 950, the two support memberscome together in the form of a distal quarter-circle 951. At theproximal end of each cage arm 950, the two support members come togetherin the form of a proximal quarter circle 958 with attached elongatelinear member 959. In one embodiment, four cage arms 950 are circularlyarranged around the helical screw pump (not shown) of the device to formthe basket-like cage support structure. The four distal quarter-circles951 are attached to the distal end cap (not shown) and inner shaftportion (not shown) of the pump at the distal end of the device. Thefour proximal quarter-circles 958, with attached elongate linear members959, are attached to a housing (not shown) supporting the motor (notshown) at the proximal end of the device.

FIG. 9C is a top-down view illustration of the same embodiment of twocage support members 920 formed together into a singular cage arm 950 inthe expanded configuration of FIG. 9A. In one embodiment, the central,thin rectangular shaped portion 921 of each cage support member 920 iscomposed of stainless steel. In this embodiment, the rigidity of thisportion 921 lends stability to the device. In another embodiment, thecentral, thin rectangular shaped portion 921 of each cage support member920 is composed of a shape memory metal. In one embodiment, the shapememory metal is Nitinol. In this embodiment, the flexibility of thisportion 921 allows the cage to fit more snugly within the aorta. Thisportion 921 comes to rest against the inner wall of the aorta when thedevice is deployed. Distal and proximal to each central portion 921 aretwo hinge portions 922 and 924 respectively. Each hinge portion 922, 924is composed of a shape memory metal and allows for compression andexpansion of each cage support member 920. In one embodiment, the shapememory metal is Nitinol. In one embodiment, the distal end 923 andproximal end 925 of each support member 920 are composed of stainlesssteel. This again lends overall stability to the device and allows forattachment of the support members 920 to the other components of thedevice. In one embodiment, each elongate linear member 959 is composedof stainless steel.

In one embodiment, each hinge portion 922, 924 includes at least oneslit 926 to enhance flexibility and for the passage of a wire leadingfrom a sensor positioned distally on the device. Additionally, in oneembodiment, each hinge portion 922, 924 includes an elongate tubularmember 927 along its external edge for the guiding of sensor and/orcamera wires. In one embodiment, each central rectangular portion 921includes an elongate tubular member along one side for the guiding ofsensor and/or camera wires.

FIG. 9D is a front-on view illustration of the same embodiment of twocage support members 920 formed together into a singular cage arm 950 inthe expanded configuration of FIG. 9A. Visible in FIG. 9D are the slits926 and elongate tubular members 927, 928 for the passage of sensorand/or camera wires.

FIGS. 10A, 10B, and 10C are oblique front, side, and front-on viewillustrations respectively, of one embodiment of four cage arms 1050combined together to form a complete basket-like cage 1060 in theexpanded configuration. In various other embodiments, the cage includesfewer or more than four arms and takes on a variety of other shapes,including, but not limited to, an ellipse. Referring simultaneously toFIGS. 10A and 10B, each cage arm 1050 comprises two cage support members1020 and one elongate linear member 1059. The complete cage 1060comprises four cage arms 1050 arranged together such that the distalends of each cage arm 1050 come together to form a circle 1062 at thedistal end of the device. The distal end of the cage 1060 is attached tothe distal end cap (not shown) and inner shaft portion at the circle1062. The four elongate linear members 1059 enclose a housing at theproximal end of the device and are spaced apart from one another in 90degree increments. In one embodiment, the housing contains the motor todrive the device and a battery to power the motor. In addition, in oneembodiment, the housing includes a locking mechanism to couple with thepositioning shaft. In the expanded configuration, the eight centralrectangular portions 1021 of each cage support member 1020 are expandedout away from the center of the device and from one another. FIG. 10Cillustrates the circle 1062 formed at the distal end of the cage 1060 bythe combination of four cage arms 1050.

FIGS. 11A, 11B, and 11C are oblique front, side, and front-on viewillustrations respectively, of one embodiment of four cage arms 1150combined together to form a complete basket-like cage 1160 in thecollapsed configuration. Referring simultaneously to FIGS. 11A and 11B,each cage arm 1150 comprises two cage support members 1120 and oneelongate linear member 1159. The complete cage 1160 comprises four cagearms 1150 arranged together such that the distal ends of each cage arm1150 come together to form a circle 1162 at the distal end of thedevice. The distal end of the cage 1160 is attached to the distal endcap (not shown) and inner shaft portion (not shown) at the circle 1162.The four elongate linear members 1159 enclose a housing (not shown) atthe proximal end of the device and are spaced apart from one another in90 degree increments. In the collapsed configuration, the eight centralrectangular portions 1121 of each cage support member 1120 arecompressed in toward the center of the device and are in contact withone another. FIG. 11C illustrates the circle 1162 formed at the distalend of the cage 1160 by the combination of four cage arms 1150.

FIG. 12A is a side view illustration on one embodiment of an arterialclosure device 1200, depicting the arterial closure discs 1205, 1210 ofthe device 1200 positioned within a delivery sheath 1220. The arterialclosure device is used to seal the arteriotomy site after insertion orretrieval of the pumping device of the present specification. In oneembodiment, the closure device 1200 includes a pair of opposing umbrellashaped discs 1205, 1210. The distal disc 1205 includes a concave-convexdeployed shape wherein its inner concave surface contacts the inner wallof the artery and the proximal disc 1210 includes a concave-convexdeployed shape wherein its inner concave surface contacts the outer wallof the artery. The discs 1205, 1210 are connected at their centers by adiaphragm 1207 having a lumen. Both discs 1205, 1210 are initiallyconstrained inside an elongate delivery sheath 1220, having a lumen andproximal and distal ends, and are deployed and expanded by extendingdistally from the distal tip of the delivery sheath 1220.

The delivery sheath 1220 includes a delivery sheath head 1222 at itsproximal end and handles 1227 along its length. The delivery sheath head1222 includes a distal end that attaches to the proximal end of thesheath and a proximal end. The delivery sheath head 1222 and handles1227 are used by the physician to manipulate the closure device 1200during placement. The delivery sheath 1220 includes an elongate bloodreturn tube 1224 having a proximal end and a distal end. The distal endof the blood return tube 1224 is positioned at the distal end of thedelivery sheath 1220 and the proximal end of the blood return tube 1224exits at a point between the distal and proximal ends of the deliverysheath 1220. The closure device 1200 includes a tamper tool 1230 forextending the discs 1205, 1210 beyond the distal end of the deliverysheath 1220. The tamper tool 1230 comprises an elongate shaft having atamper tool lumen, a proximal end, and a distal end and extends withinthe lumen of the delivery sheath 1220. The distal end of the tamper tool1230 abuts the proximal end of the proximal disc 1210. At its proximalend, the tamper tool 1230 includes a handle 1232 that extends beyond theproximal end of the delivery sheath head 1222. Positioned on the tampertool 1230 distal to the handle 1232 are a distal rivet 1235 and aproximal rivet 1237. During placement of the discs 1205, 1210 the distalrivet 1235 and proximal rivet 1237 sequentially engage a groove 1229positioned within the proximal end of the delivery sheath head 1222. Astring 1209 is attached to the distal disc 1205 and extends through thelumen of the diaphragm 1207, through the center of the proximal disc1210, and proximally through the tamper tool 1230 lumen.

During placement of the arterial closure discs 1205, 1210, the entiresheath system is advanced over the wire 1240 extending from the distalend of the pumping device. The wire 1240 extends through the tamper toollumen and guides the closure device 1200. If arterial closure is beingperformed after removal of the pumping device, a separate guide wire isfirst introduced into the artery. For arterial closure after theinsertion of the pumping device, the delivery sheath 1220 of the closuredevice 1200 is delivered through the existing arterial sheath used toinsert the pumping device.

FIG. 12B is a side view illustration of the same embodiment of thearterial closure device 1200 of FIG. 12A, depicting the distal arterialclosure disc 1205 expanded and deployed from the distal end of thedelivery sheath 1220. Once the distal end of the delivery sheath 1220 ispositioned inside the artery 1250, as confirmed by the presence of blood1255 at the proximal end of the blood return tube 1224, the distal disc1205 of the closure device 1200 is pushed out with the tamper tool 1230.Once beyond the distal end of the delivery sheath 1220, the distal disc1205 expands to its umbrella shape. The tamper handle 1232 is pusheddistally into the delivery sheath head 1222 until the distal rivet 1235engages the groove 1229, effectively locking the tamper tool 1230 inplace. The entire closure device 1200 is then pulled back so that theumbrella shaped distal disc 1205 opposes the hole in the artery from theinside. The existing arterial sheath for inserting the pumping device isthen removed and the delivery sheath 1220 is left just outside theartery 1250.

FIG. 12C is a side view illustration of the same embodiment of thearterial closure device 1200 of FIG. 12A, depicting both the distal 1205and proximal 1210 arterial closure discs expanded and deployed from thedistal end of the delivery sheath 1220. The reverse umbrella shapedproximal disc 1210 of the closure device 1200 is delivered to theoutside of the artery 1250 by simultaneously pulling back the deliverysheath 1220 and pushing in the tamper tool handle 1232 until thedelivery sheath head 1222 and tamper tool handle 1232 are fully apposed.In this position, the proximal rivet 1237 of the tamper tool 1230engages the groove 1229 of the delivery sheath head 1222, effectivelylocking the tamper tool 1230 in place. In one embodiment, the deliverysheath head 1222 is pushed distally along the delivery sheath 1220,wherein the delivery sheath 1220 includes a rivet 1225 that engages asecond groove 1221 within the delivery sheath head 1222, effectivelylocking the delivery sheath 1220 in place within the delivery sheathhead 1222. The delivery sheath 1220, with the delivery sheath head 1222,and the tamper tool 1230 are then removed.

FIG. 12D is a side view illustration of one embodiment of the arterialclosure discs 1205, 1210 fully deployed with the delivery sheathremoved. The distal disc 1205 is depicted within the artery 1250 and theproximal disc 1210 is depicted outside the artery 1250. The two apposingdiscs 1205, 1210 with center diaphragm 1207 seal the arteriotomy site.Once both discs 1205, 1210 are in place, the sheath and tamper arepulled out, exposing only the string 1209 attached to the distal disc1205. Once arteriotomy closure is confirmed, the string 1209 is cutbelow the skin. The guide wire in the center can be removed if necessaryfrom the center diaphragm 1207 keeping the artery 1250 sealed.

FIG. 12E is an illustration of one embodiment of the arterial closurediscs 1205, 1210, depicting the struts 1204 used to expand the discs1205, 1210 to their deployed configuration. The discs 1205, 1210 areconstricted and tubular shaped, as depicted in FIG. 12A, whenconstrained in the restraining sheath and expand into umbrella shapeddiscs 1205, 1210 outside the sheath, as depicted in FIG. 12E. Theproximal surface 1203 of the proximal disc 1210 indicates the pointwhere the tamper tool pushes on the discs to deploy them from thesheath. In one embodiment, the discs are made out of an expandable andbiocompatible material. The discs 1205, 1210 include a diaphragm 1207interconnecting them with a lumen 1208 in the center to accommodate thestring and guide wire exiting the artery. Each disc 1205, 1210 alsoincludes a hole at its center for accommodation of the string and guidewire. The radiating struts 1204 act to expand the discs into theirumbrella shape upon deployment.

FIG. 13 is a flowchart illustrating the steps involved in implanting thehemodynamic flow assist device in the descending aorta of a patient, inaccordance with one embodiment of the present specification. At step1302, a physician creates an access point in the femoral artery of apatient. A sheath with a guide wire is inserted into the femoral arteryand advanced such that the distal end of the sheath is positioned withinthe descending aorta at step 1304. Then, at step 1306, the hemodynamicflow assist device, in the collapsed configuration, is inserted into thesheath and is advanced along the guide wire. At step 1308, a positioningdevice attached to the proximal end of the flow assist device is used toadvance the flow assist device beyond the distal end of the sheath,causing the flow assist device to passively transform from its collapsedconfiguration into its expanded configuration. At step 1310, thepositioning device is used to position the flow assist device within thedescending aorta. The positioning device is then uncoupled from the flowassist device at step 1312. At step 1314, the positioning device andsheath with guide wire are removed from the patient. The access point isthen closed at step 1316.

FIG. 14 is a flowchart illustrating the steps involved in closing anarterial access point using the arterial closure device, in accordancewith one embodiment of the present specification. At step 1402, aphysician inserts a guide wire into the artery through the access point.The proximal end of the guide wire is inserted into the lumen of thetamper tool and the closure device is advanced along the guide wire atstep 1404. The distal end of the closure device is positioned in theinterior of the artery at step 1406. Then, at step 1408, the handle ofthe tamper tool is pushed to advance the distal disc beyond the distalend of the sheath, causing the distal disc to passively transform fromits compressed configuration into its expanded configuration within theartery. At step 1410, the closure device is pulled back to position thedistal disc against the inner wall of the artery. Then, at step 1412,the handle of the tamper tool is pushed to advance the proximal discbeyond the distal end of the sheath, causing the proximal disc topassively transform from its compressed configuration into its expandedconfiguration outside the artery. The closure device and guide wire arethen removed from the patient at step 1414.

The above examples are merely illustrative of the many applications ofthe system of the present invention. Although only a few embodiments ofthe present invention have been described herein, it should beunderstood that the present invention might be embodied in many otherspecific forms without departing from the spirit or scope of theinvention. Therefore, the present examples and embodiments are to beconsidered as illustrative and not restrictive, and the invention may bemodified within the scope of the appended claims.

We claim:
 1. An arterial closure device comprising: an elongate sheathhaving a sheath lumen, a proximal end, a distal end and a sheath headhaving a proximal end and a distal end attached to said proximal end ofsaid sheath; an elongate tool having a tool lumen and disposed withinsaid sheath lumen, wherein the elongate tool has a proximal end and adistal end, wherein said proximal end of said tool extends beyond saidproximal end of said sheath, and wherein said tool includes a handle atsaid proximal end; a distal disc positioned within said distal end ofsaid sheath; a proximal disc positioned within said distal end of saidsheath, proximal to said distal disc and in contact with said distal endof said tool; and a center member connecting said discs; wherein saiddiscs are transformable between a compressed tubular configuration andan expanded configuration and wherein said discs are adapted to bedeployable beyond said distal end of said sheath by pushing on saidhandle of said tool such that said tool moves distally into said sheathand pushes said discs out said distal end of said sheath, furtherwherein said discs are in said compressed tubular configuration whendisposed within said sheath and are in said expanded configuration whenadvanced beyond said distal end of said sheath and wherein, when saiddiscs are deployed in said expanded configuration, said distal disc isadapted to be positioned within an artery and said proximal disc isadapted to be positioned outside said artery to seal said artery.
 2. Thearterial closure device of claim 1, wherein, when in said expandedconfiguration, said distal disc has an umbrella shape and said proximaldisc has an inverted umbrella shape.
 3. The arterial closure device ofclaim 1, wherein, when deployed, said distal disc has a concave-convexshape, wherein a concave surface of said distal disc contacts an innerwall of said artery, and said proximal disc has a concave-convex shape,wherein a concave surface of said proximal disc contacts an outer wallof said artery.
 4. The arterial closure device of claim 1, wherein saidcenter member comprises a diaphragm having a lumen.
 5. The arterialclosure device of claim 4, wherein said distal disc further comprises ahole at a center of said distal disc and wherein said proximal discfurther comprises a hole at a center of said proximal disc.
 6. Thearterial closure device of claim 5, further comprising a string attachedto said distal disc and extending through said lumen of said diaphragm,said hole of said proximal disc, and said tool lumen.
 7. The arterialclosure device of claim 1, wherein said tool includes a proximal rivetand a distal rivet positioned distal to said handle and wherein saidsheath head includes a first groove within its proximal end.
 8. Thearterial closure device of claim 7, wherein, when said handle of saidtool is pushed distally into said sheath head, said distal rivet engagessaid first groove and said distal disc extends beyond said distal end ofsaid sheath.
 9. The arterial closure device of claim 7, wherein, whensaid handle of said tool is pushed distally into said sheath head, saidproximal rivet engages said first groove and said proximal disc extendsbeyond said distal end of said sheath.
 10. The arterial closure deviceof claim 9, wherein said sheath includes a rivet and said sheath headincludes a second groove for engaging said rivet of said sheath andlocking said sheath within said sheath head.
 11. The arterial closuredevice of claim 1, further comprising a blood return tube having aproximal end which exits at a point between said distal and proximalends of said sheath and a distal end positioned at said distal end ofsaid sheath for confirming the positioning of said distal end of saidsheath within said artery by the presence of blood at said proximal endof said blood return tube.
 12. The arterial closure device of claim 1,further comprising handles along a length of the arterial closure devicefor manipulating said arterial closure device during placement.
 13. Thearterial closure device of claim 1, wherein at least one of saidproximal and distal discs comprise an expandable and biocompatiblematerial.
 14. The arterial closure device of claim 1, wherein at leastone of said proximal and distal discs comprise radiating struts toexpand each of said proximal and distal discs into their respectivedeployment shapes.